I am continuing my journey of converting to top entrance and I am not liking my shims cut awkwardly on a band saw. I cannot remember why it is not possible to just raise the top board up 3/8" and block it on three sides and leave one side open. Does this create too much space for the bees to build unwanted stuff?

Or cut an opening in a standard top board?

Also I have been using solid bottom boards, I think because of advice from a talk by Michael Bush here locally in Virginia. In 2005 Michael said in a forum that he used SBB on all 50 of his hives. I think he is now up to 200. Still using SBB Michael?